Centralized lighting control systems are known in the art. Typically, the central computer controls the lighting system throughout a building or other facility, such as is defined by the DALI standard, a well-known lighting control standard. The lighting device being controlled interfaces to the central computer through a serial interface. A microprocessor at the lighting device usually performs serial to parallel conversion of incoming commands and data, error detection, and arbitration control between incoming and outgoing data and commands.
FIG. 1 shows typical prior art interface into a DALI control computer. The control computer 107 receives and transmits various data and commands serially over lines 103 and 104 as shown. A microprocessor 101 is employed at the lighting device to receive and process the commands and to control other elements of the lighting device over parallel bus 102. Functions executed by microprocessor 101 include error detection and correction, serial to parallel conversion, and edge detection, as required by the DALI standard. Control of arbitration of communications into and out of the lighting device is also implemented within microprocessor 101.
One problem with prior art systems such as that of FIG. 1 is that for cost reasons, microprocessor 101 is typically a basic low end capability processor such as an 8051. The tasks required to be performed by microprocessor 101 results in significant loading on the processor's limited capabilities, and decreased performance. The foregoing is true particularly with respect to error detection and correction algorithms, where significant mathematical processing may be required.
In view of the foregoing, there exists a need in the art for an improved technique of interfacing with a central lighting control computer that controls one or more lighting devices using a standard set of commands and a predetermined protocol.
There also exists a need in the art for an improved technique of minimizing the processing load presented to the basic capability microprocessors typically employed by a DALI compliant lighting device being controlled by a control computer.